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Efficacy of a Pacemaker Algorithm in Promotion of the Intrinsic Heart Activity.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00156741
Recruitment Status : Unknown
Verified September 2005 by Medtronic BRC.
Recruitment status was:  Active, not recruiting
First Posted : September 12, 2005
Last Update Posted : August 2, 2011
Information provided by:
Medtronic BRC

Brief Summary:
The purpose of this study is to provide evidence that the Refined Ventricular Pacing Algorithm leads to clinically relevant reduction (at least 50% reduction) of the incidence of ventricular pacing.

Condition or disease Intervention/treatment Phase
Bradycardia; Sick Sinus Syndrome, AV Block Device: Vitatron C50 D Model C50A2 of Vitatron C60 DR model C60A2 Procedure: Required pacemaker setting Phase 4

Detailed Description:

Electrical stimulation in the apex of the right ventricle ( ventricular pacing) usually improves the heart function of patients with a pacemaker and can even be life-saving. However, evidence is accumulating that ventricular pacing may also have undesired long-term cardiac effects. Therefore, it makes sense to limit ventricular pacing to the absolute required minimum. The functionality RVP (Refined Ventricular Pacing) in the C-series 2nd generation pacemakers of Vitatron B.V. Arnhem, the Netherlands is designed to reduce ventricular pacing.

After implantation of the Vitatron C50 D model C50A2 (pacemaker) or Vitatron C60 DR model C60A2 (pacemaker) and a 4-6 weeks stabilization period, proper functioning of pacemaker and leads (stimulation- and sensing parameters) is checked. The pacemakers will be programmed according to predefined settings.

In the following 4-weeks Baseline period diagnostic data (atrial fibrillation burden and percentage of ventricular pacing (% VP)) are collected in the pacemaker memory. Based on these data, patients will be excluded from further participation (patients with more than 15% atrial fibrillation) or subdivided into three groups: (a) < 30% VP (30- VP group), (b) >30% VP, Sick Sinus Syndrome and normal conductivity (SSS group), (c) >30% VP, 1st or 2nd degree AV block. Patients in these three groups will be treated for 4 weeks alternatively with the RVP functionality switched ON or OFF. The order will be determined by randomization. At the end of these two cross-over periods the % VP and the judgment of the patients of the last period will be assessed. Adverse events will be recorded from the moment of study enrolment.

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Study Type : Interventional  (Clinical Trial)
Enrollment : 150 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: IntAct, Study on Promotion of Intrinsic Activity.
Study Start Date : April 2004
Study Completion Date : April 2006

Resource links provided by the National Library of Medicine

Primary Outcome Measures :
  1. Calculation of reduction in % VP when RVP algorithm is ON versus OFF, recording % VP at 4 and 8 weeks after randomization

Secondary Outcome Measures :
  1. Occurrence of possible undesired consequences of the RVP algorithm (e.g. retrograde conduction; AF burden) and adverse events in the periods with the algorithm switched ON versus OFF, 4 and 8 weeks after randomization
  2. Patient's opinion about treatment (on a six-point scale), at 4 and 8 weeks after randomization
  3. explorative subanalysis on patients with different arrhythmias and/or conducting system defects to investigate in which type of patients the RVP algorithm will have the largest impact on %VP
  4. Reproducibility of the %VP assessment, comparison %VP during Baseline periode and 4-week study period with RVP OFF

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients shall be willing to sign the Patient Informed Consent for this study
  • Patients shall have at least one of the following indications for a pacemaker: - Sick Sinus Syndrome with normal QRS complexes
  • First degree AV block with a PR interval <_220 ms for patients <_ 70 years of age, or <_ 260 for patients over 70 years
  • Second-degree AV block, mobitz I (wenckebach) or mobitz II
  • Patients shall be available for follow-up for the duration of their participation.

Exclusion Criteria:

  • Patients involved in another investigation study conducted in parallel to this study
  • Patients younger than 18 years of age and/or patients that do NOT meet other local requirements for participation
  • Pregnant patients
  • Patients with lead integrity problems (and the lead is not being replaced)
  • Patients with persistant AF
  • Patients with a complete AV block
  • Patients with NYHA (New York Heart Association0 class III and IV
  • Patients who underwent thoracic surgery in the last three months or are expected to have in the near future
  • Patients with a 2:1 block
  • Patients with a life expectancy less than half a year

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00156741

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Sponsors and Collaborators
Medtronic BRC
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Study Chair: Ludwig Binner, MD Universitätsklinikum Ulm, Ulm, Germany
Study Director: Chris van Groeningen, MD Vitatron B.V., Arnhem, The Netherlands

The MOST Trial Investigators. Effect of pacing mode and cumulative percent time ventricular paced on heart failure in patients with sick sinus syndrome and baseline QRS duration < 120 milliseconds in MOST. PACE 2002; 561 Abstract 155.
The MOST Trial Investigators. Baseline QRS duration ≥ 120 milliseconds and cumulative percent time ventricular paced predicts increased risk of heart failure, stroke and death in DDDR-paced patients with sick sinus syndrome in MOST. PACE 2002; 690 Abstract 672
Andersen HR, Kristensen L, Nielsen JC, Mortensen PT, Pedersen OL, Pedersen AK, Atrial verses dual chamber pacing in patients with sick sinus syndrome, atrial fibrillation, congestive heart failure and mortality during follow-up in a randomised trial of 177 patients. PACE 2001; 24: 575 Abstract 174
Boute W, Brunekreeft W. AV delay hysteresis in dual chamber pacing: initial results from the Ruby Clinical Investigation. Vitatext 1994; 1: 13-14
Connolly SJ, Talajic M, Roy D, Tang ASL, Lav C, Bonilla L, Gillis AM. The effect of pacemaker selection on functional capacity in the Canadian Trial of Physiologic Pacing (CTOPP). Circulation 1999; 100(suppl I): I-465
Kristensen L, Nielsen JC, Andersen HR. Outcome of patients with sick sinus syndrome treated by different pacing modalities. In Ovsyshcher IE (ed): Cardiac arrhythmias and device therapy results and perspectives for the new century. Futura Publishing Company Inc., Armonk NY, 2000, 323-332.
Nielsen JC, Kristensen L, Pedersen AK, Mortensen PT, Pedersen OL. Changes in left atrial size and left ventricular size and functioning during follow-up of 177 patients with sick sinus syndrome randomised to atrial or dual chamber pacing. PACE 2001; 24: 697 Abstract 633
Woodend K, Tang SI, Irvine J, Connolly S, Lav C, Paquette M, Newman D. Pacemaker dependency conditions the QOL benefits of physiologic over VVI pacing: Canadian Trial of Physiologic Pacing (CTOPP). Circulation 1999; 100(suppl I): I-20

Layout table for additonal information Identifier: NCT00156741     History of Changes
Other Study ID Numbers: CMD 287
First Posted: September 12, 2005    Key Record Dates
Last Update Posted: August 2, 2011
Last Verified: September 2005
Keywords provided by Medtronic BRC:
Refined ventricular pacing
Additional relevant MeSH terms:
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Sick Sinus Syndrome
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Arrhythmia, Sinus
Heart Block
Cardiac Conduction System Disease